Summary & Overview
HCPCS G6021: Unlisted Procedure, Intestine
HCPCS Level II code G6021 designates an unlisted procedure of the intestine and is used when an intestinal procedure lacks a specific HCPCS Level II descriptor. Nationally, unlisted procedure codes like G6021 matter because they require supplemental documentation to describe the service provided, influencing claim adjudication, medical necessity review, and pricing pathways across payers. Typical sites of service include hospital inpatient units, hospital outpatient departments, and ambulatory surgical centers where intestinal surgeries and interventions occur. Key payers addressed in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.
Readers will find a concise explanation of the code’s clinical scope and service settings, what payers commonly require for unlisted intestinal procedures, and an overview of documentation and coding considerations that affect claim processing. The publication summarizes common policy positions across major national payers, highlights benchmarking and reimbursement implications for unlisted intestinal procedures, and outlines the clinical context in which G6021 is typically reported. Data not available in the input will be noted where applicable.
Billing Code Overview
HCPCS Level II code G6021 is an unlisted procedure for the intestine. This code is used to report intestinal procedures that do not have a specific, predefined HCPCS Level II code.
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Service type: Surgical or procedural intervention on the intestine
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Typical site of service: Hospital inpatient, hospital outpatient department, or ambulatory surgical center depending on the specific procedure and clinical setting
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A typical patient is a 62-year-old with a history of recurrent small bowel obstruction and chronic ischemic segment of the ileum, admitted for surgical exploration when nonoperative measures fail. The patient presents with abdominal pain, vomiting, and radiographic evidence of an intestinal lesion requiring an operative procedure that does not match an established CPT code because the resection or repair involves an unusual location, complex reconstruction, or a novel technique. The clinical workflow begins with preoperative evaluation by a general surgeon or colorectal surgeon, anesthesia clearance, and informed consent noting the unlisted intestinal procedure. Intraoperatively the surgeon documents detailed operative steps, extent of resection or repair, length of bowel involved, anastomosis technique, and any grafts or conduits used. Postoperative documentation includes immediate findings, complications, and rationale for using an unlisted intestine procedure code. Billing includes G6021 with a complete operative report, relevant ICD-10 diagnosis codes, and any applicable modifiers to indicate bilateral procedures, reduced services, or professional/surgical components as required by the payer. Typical sites of service are hospital inpatient operating room, hospital outpatient surgical suite, or ambulatory surgery center depending on clinical acuity and expected postoperative care.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
25 | Significant, separately identifiable evaluation and management service by the same physician on the day of a procedure | Use when preoperative E/M is significant and distinct from the surgical service for G6021. |
57 | Decision for surgery | Use when the E/M service resulted in the decision to perform the surgical procedure billed as G6021 on the same day.
59 | Distinct procedural service | Use to indicate a separate, distinct procedure or service provided on the same day as G6021 when other CPTs are billed.
78 | Return to OR for a related procedure during postoperative period | Use when the patient returns to the operating room for a related intestinal complication after G6021.
79 | Unrelated procedure or service by the same physician during postoperative period | Use when an unrelated procedure is performed during the global period following G6021.
GT | Via interactive audio and video telecommunication | Use when qualifying telemedicine services are furnished in conjunction with perioperative care for the patient undergoing the unlisted intestinal procedure.
26 | Professional component | Use when billing separates professional component of a service related to G6021 (e.g., pathology professional component billed separately).
TC | Technical component | Use when billing the technical component of a related service (e.g., facility technical portion of intraoperative imaging) in conjunction with G6021.
24 | Unrelated E/M service during global period | Use when an unrelated E/M service is provided during the global surgical period for G6021.
LT | Left side | Use when the unlisted intestinal procedure can be anatomically identified as left-sided and payer requires laterality reporting.
RT | Right side | Use when the unlisted intestinal procedure can be anatomically identified as right-sided and payer requires laterality reporting.
CA | Procedure performed in a caesarean delivery | Use when an intestinal procedure is performed in conjunction with a cesarean delivery where applicable.
AA | Anesthesia services performed personally by anesthesiologist | Use when anesthesia is personally provided by the anesthesiologist for the case involving G6021.
QK | Medical direction of 2–4 anesthesia services | Use when the anesthesiologist medically directs multiple anesthesia services for the procedure associated with G6021.
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207P00000X | General Surgery | Most common specialty performing exploratory or resectional intestinal procedures requiring an unlisted code. |
207V00000X | Colon and Rectal Surgery | Specialty for complex colorectal resections or reconstructions when standard CPTs are inadequate.
208800000X | Gastroenterology | May perform certain endoscopic intestinal procedures but less commonly uses unlisted intestinal surgery codes; included for diagnostic/therapeutic crossover.
186L00000X | Surgical Oncology | Involved when intestinal procedures are performed for malignancy requiring atypical resection or reconstruction.
207LP2900X | Pediatric General Surgery | Relevant when unlisted intestinal procedures are performed in pediatric patients with congenital or complex anatomy.
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
K56.60 | Paralytic ileus, unspecified | Common indication for surgical exploration when conservative management fails and an unlisted intestinal procedure may be required. |
K56.69 | Other intestinal obstruction | May prompt operative intervention with procedures that do not fit standard CPT descriptors, leading to use of G6021.
K63.1 | Perforation of intestine (nontraumatic) | Intestinal perforations can require nonstandard repairs or resections documented under G6021.
K55.9 | Vascular disorder of intestine, unspecified | Ischemic segments requiring atypical resection or reconstruction can necessitate an unlisted intestine procedure.
C18.9 | Malignant neoplasm of colon, unspecified | Complex oncologic resections that are not fully described by standard CPT codes may be billed as G6021 with supporting operative detail.
K57.50 | Diverticulitis of large intestine without perforation or abscess | Complicated diverticular disease with unusual resection or repair may be reported with G6021.
K50.00 | Crohn's disease of small intestine without complications | Crohn disease can cause atypical resections or reconstructions when standard CPTs are not suitable, supporting use of an unlisted intestine code.
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
44120 | Enterectomy, resection of small intestine; single resection and anastomosis | Commonly used for standard small bowel resections; if the operative approach or complexity is atypical it may be billed instead as G6021 with documentation explaining differences. |
44140 | Enterolysis (freeing of intestinal adhesion) | Performed when adhesions cause obstruction; may be billed alongside or instead of G6021 depending on extent and uniqueness of procedure.
44204 | Laparoscopy, surgical; colectomy, partial, with anastomosis | Standard laparoscopic partial colectomy code; complex or nonstandard intestinal resections not described by existing CPTs may use G6021.
44160 | Colectomy, partial; with anastomosis, for other than neoplasm | Used for partial colectomy; when resection spans unusual segments or requires complex reconstruction, G6021 may be more appropriate.
44125 | Enterostomy, resection and anastomosis, with creation of stoma (e.g., ileostomy) | When creation of a stoma accompanies resection and the combined technique is atypical, G6021 may be reported with an explanatory operative report.